Adams



No. 748,904. PATENTED JAN. 5, 1904* L. WIRTZ & T. HAMILTON-ADAMS.

ELECTRIC ARC LAMP.

APPLICATION FILED FEB. 4, 1903.

N0 MODEL.

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UNITED STATES Patented January 5, 1904.

PATENT OFFICE.

ELECTRIC-ARC LAMP.

SPECIFICATION forming part of Letters Patent No. 748,904, dated January5, 1904.

Application filed February 4,1903. Serial No. 141,887. (No model.)

To aZZ whom it may concern:

Be it known that we, LUIS WIRTZ, a subject of the King of Spain, andTHOMAS HAMILTON- ADAMS, a subject of the King of Great Britain, bothresiding at Howard House, Arundel street, Strand, London, England, haveinvented new and useful Improvements in Electric-Arc Lamps, of which thefollowing is a specification.

This invention relates to improvements in electric-arc lamps of the kindwherein the movable carbon is moved toward the fixed carbon by gravityand is raised by a solenoid-core which automatically grips the movablecarbon-holder or carbon through the medium of a suitable catch orclutch, the object being to overcome certain disadvantages attaching toarc-lamps of this description as heretofore made and also to simplifythe construction and provide means whereby the length of arc and thequantity of current passing through the lamp can be varied as desired.

To enable our invention to be fully understood, we will describe it byreference to the accompanying drawings, in which Figure 1 represents asectional elevation of an inclosed arc-lamp having the improvementsapplied thereto; and Fig. 2 is a section on the line 2 2, Fig. l.

a is the casing of the lamp; b, the globe, which is attached to theframe by hermetic joints on the bottom of the casing a and of the frameor, carrying the lower carbon, so that the casing and globe b form aninclosed space. 0 is the upper carbon, and d the lower carbon.

In lamps of this description as heretofore made when current is firstpassed through the solenoid it raises the upper carbon 0 too quickly andtoo far and in the working of the lamp causes pumping or unsteadiness inthe are produced, so that it has been foundnecessary to provideindependent mechanism for controlling this movement. Now we overcomethis disadvantage by making use of a special form of solenoid in whichthe full magnetic force is not generated immediately on the flow of thecurrent and in which the lines of force are limited to a restrictedfield. The drawings show a suitable form of this solenoid and consistsof two half-bobbins e e, secured by a central non-magnetic tube orlining f-say of brass-an annular space 9 being left between the innerends of the two half-bobbins e 6 around the said lining f. This spacemay be either filled with air or with another non-magnetic substance,such as brass. Around the outside of the two half-bobbins e c andbetween the flanges thereof we fit a thickness or cylinder h, of mica orother non-conducting material, upon which the solenoid-coil h is wound,the whole being inclosed in a tightly-fitting jacket 2', of iron,secured to the flanges of the two halfbobbins e e. For direct workingthe core comprises the iron plug j, which is solid at its lower end, theupper part being bored out (and preferably filled, as shown, with anonmagnetic substance, such as brass) and the lower end of the said boretapering to a point, as shown atj. The weights of the corej and of theparts raised by the said core are Wholly or partially counterbalanced bymeans of the weight 70, which is attached to the end of a cord Z0,passed over the pulley k pivotally mounted on the bracket k fixed insidethe casing C6, the other end of the cord is being attached to the top ofthe corej.

We have found that by using a solenoid of the above-describedconstruction the current when caused to flow through the coil must firstsaturate the solenoid before exerting its full pull upon the core, sothat the carbon, which is in connection with the solenoid-core, is notraised suddenly, as has heretofore been the case with lamps of thisconstruction, but gradually and regularly.

The clutch for the carbon 0 consists of the frame Z, which incloses thecarbon 0 (see Fig. 2) and has pivoted at its lower part twogravity-catches Z Z, which normally tend to drop, and so grip thecarbon. This frame Z is pivoted to the forked or slotted end of a lever'm, the other end of which is pivoted at m to a bracket m in the casinga. The lever m is arranged underneath the solenoid-core j, which isprovided with an eye it, through which the said lever passes, and with aroller '11, upon which the said lever rests, so that as the said corerises and falls the said lever follows its movements. The frame Z,carrying the gravity-catches Z Z, when in its lowermost posi- Vcertained the nature of our said invention and tion rests upon thestop-plate 0, so that the said gravity-catches are raised, as shown inFig. 1, thereby releasing the carbon. When, however, the solenoid-coreis drawn into the solenoid by the current flowing through it, it raisesthe free end of the lever m, and so allows the catches Z Z to drop andgrip the carbon c,which is thus raised with the lever 'm.

In practice we find it advantageous to make the relative lengths of thetwo arms of the lever m such that the movements of the solenoid-core jare considerably multiplied at that end controlling the gravity-catchesZ, so that the apparatus is made very sensitive to the movements of thecore j.

The stop-plate o for the gravity-catches Z is formed with twoguide-sleeves 0 0 the latter of which works upon the upper end of one ofthe tubes of the frame a, carrying the globe of the carbon, which saidend extends into the casing Ct, as clearly shown. The other sleeve 0 isinternally screw-threaded and works upon the screw-threaded rod 1),which passes up through the other tube of the frame a and is provided atits lower end with a knob or button g, by means of which it can beturned. With this arrangement it will be clear that by turning the saidrod 19, which is prevented from moving longitudinally, the stop-plate 0can be raised or lowered, as desired, so as to vary the length of arc.

In the case of singly-burning lamps, as shown in the drawings,weprovide,in conjunction with this means of adjustment, a rheostat r orresistance-box mounted inside the casing a and the movable contacts ofwhich is secured to the upper end of the rodp. With this construction itwill be evident that as the position of the stop-plate 0 is adjusted themovable contact 3 of the rheostat is also moved, so as to vary theresistance in the lamp-circuit, and thus control the current flowingthrough the same.

In the case of lamps burning in series we provide an adjustable stop 25inside the casing a, this stop serving to limit the upward movement ofthe lever m, so as to prevent the core j from being drawn into thesolenoid farther than is desired.

As above described, the casing Cb and globe b are'made air-tight, so asto prevent the entrance of air. In order to provide for the eX- pansionof the gases inside the lam p,we make use of the sliding cap or piston14, which is here shown applied to the top of the casing (1, although itcan be applied in any other suitable position. This sliding cap movesover a neck a on the casing and is normally held in its lowermostposition by means of the springs t 12. With this arrangement the slidingcap it yields under the increase of pressure of the gas inside the lampand is returned by the springs o to its normal position as the pressurebecomes readjusted.

Having now particularly described and as in what manner the same is tobe performed, we declare that what we claim is- 1. In an electric-arclamp, the combination with a holding device for engaging the movablecarbon thereof, of a solenoid having two separated half-bobbins mountedon a tube of non-magnetic material so as to leave an annular spacebetween their adjacent ends, a coil surrounding said bobbins andinsulated therefrom, an iron jacket surrounding said coil, a core withinsaid solenoid having a portion thereof bored out to reduce the effect ofthe solenoid thereon and connections between said core and thecarbon-holding device, substantially as described.

2. In an electric-arc lamp, the combination with a holding device forengaging the movable carbon thereof, of a solenoid having two separatedhalf-bobbins mounted on a tube of non-magnetic material, a coilsurrounding said bobbin and insulated therefrom, a jacket of magneticmaterial surrounding said coil, a core within said solenoid andconnections between said core and the carbon-holding device,substantially as described.

3. In an electric-arc lamp, the combination with a holding device forthe movable carbon, of a solenoid having two separated half-bobbinsmounted on a tube of non-magnetic material so as to leave an annularspace between them, a coil surrounding said bobbins and insulatedtherefrom, an iron jacket surrounding said coil, a core within saidsolenoid having a portion thereof bored out to reduce the effect of thesolenoid thereon, a counterbalance connected with said core andconnections between said core and the carbon-holder, substantially asdescribed.

4:. In an electric-arc lamp, the combination with a vertically-movableframe, of a pair of pivoted gravity-pawls mounted therein for holdingthe movable carbon, a solenoid located at one side of the movablecarbon, a movable core located therein, a friction-roller secured tosaid core, a lever pivoted to the lamp-casing and to said movable frame,and engaging said friction-roller, and a counterbalance connected withsaid core, substantially as described.

5. In an electric-arc lamp, the combination with a vertically-movableframe, of a pair of pivoted gravitypawls mounted therein for holding themovable carbon, a solenoid located at one side of the movable carbon, amovable core located therein, a lever pivoted to the lamp-casing and tosaid frame, said core having a part provided with a frictionrollerengaging said lever, a counterbalance weight, a flexible connectionbetween said weight and said core and a stationary roller engaging saidflexible connection, substantially as described.

6. In an electric-arc lam p, the combination with a vertically-movableframe, of a pair of pivoted gravity-pawls mounted therein for holdingthe movable carbon, a solenoid located at one side of the movablecarbon, a movable core located therein, a lever connected to said frameand having a connection with the said core, a vertically-adjustablestop-frame, adapted to engage said pawls, to raise them in respect totheir supportingframe, and a rod extending outside of the lamp-casing,having a threaded portion engaging said stop-frame for adjusting thesame, substantially as described.

7. In an electric-arc lamp mechanism for raising the movable carbon,comprising a vertically-movable frame, a pair of gravitycatches forengaging the movable carbon, a stop for engaging said catches to causethem to release the carbon, a rheostat within the lamp-casing, anadjusting device for said stop, and a connection between said adjustingdevice and said rheostat for operating the same simultaneously with theadjustment of said stop, substantially as described.

8. In an electric-arc lamp, the combination with the casing, and closedglobe communieating therewith, a sliding piston having a face incommunication With the interior of said chamber and springs connectedwith said piston, substantially as described.

9. In an arc-lamp, the combination with the casing provided With anaperture and acylindrical part surrounding said aperture, of a slidingcap fitting over said cylindrical part, springs connecting said cap withsaid casing and a globe communicating with said casing, substantially asdescribed.

LUIS WIRTZ. THOMAS HAMILTON-ADAMS.

Witnesses:

JOHN E. BOUSFIELD, O. G. REDFERN.

